NED Abstract

Copyright by American Astronomical Society.
Reproduced by permission
1994AJ....107..118B
MEAN MORPHOLOGICAL TYPES OF BRIGHT GALAXIES
R. BUTA
Department of Physics and Astronomy, University of Alabama, Tuscaloosa,
Alabama 35487
Electronic mail: buta@ualvm.bitnet
S. MITRA AND G. DE VAUCOULEURS
Department of Astronomy, University of Texas, Austin, Texas 78712
Electronic mail: gav@astro.as.utexas.edu
H. G. CORWIN, JR.
IPAC, M/S 100-22, Caltech, Pasadena, California 91125
Electronic mail: hgcjr@ipac.caltech.edu
Received 1993 June 21; revised 1993 September 7
ABSTRACT
The revised Hubble classifications provided in the Third Reference
Catalogue of Bright Galaxies are based on nine lists and catalogues, both
published and unpublished, from five observers. This paper describes the
procedures that were used to combine these classifications into mean
classifications including the family, variety, and stage. The best
classifications in RC3 are based on large-scale photographic images taken
with 1.5-5 m class reflectors. However, most of the types in RC3 are
based on the small-scale prints, plates, and films of the first Palomar
Sky Survey and the UK Schmidt IIIa-J Southern Sky Survey. The overlap
between the different observers samples allowed determination of the
reliability of sky survey types and the effects of diameter and
inclination on the accuracy of these types. We find that for a typical
galaxy having isophotal diameter D_25_ ~ 2' and inclined by ~ 50^deg^,
types T from the sky surveys have a mean error (averaged over all of the
observers) of {sigma}({TAU}) = 0.7 step on the numerical scale of the
revised Hubble system. With the new database of classifications, we
rederive the classical relations between Hubble type and integrated
colors, surface brightnesses, and hydrogen index (hydrogen flux to blue
light ratio) for a large sample of galaxies. We also present a table of
galaxies which we consider to be representative examples of each type.